


Join

by RurouniHime



Series: Joined 'verse [2]
Category: The Avengers (Marvel Movies)
Genre: Alpha/Beta/Omega Dynamics, Alpha/Omega, Bonding, Established Relationship, Explicit Sexual Content, Hurt Steve, M/M, Mating Cycles/In Heat, Mpreg, Pregnant Sex, Protective Steve, Steve needs a break, Team Dynamics, Tony Stark Feels, Tony can't figure out how to give him one
Language: English
Status: Completed
Published: 2015-07-25
Updated: 2015-07-25
Packaged: 2018-04-11 04:52:42
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 5,606
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4422113
Author URL: https://archiveofourown.org/users/RurouniHime/pseuds/RurouniHime
Summary: <blockquote class="userstuff">
              <p>
  <i>In the beginning, it was exquisite. Ingenious of nature to come up with this, he’d thought, soaked in sweat and indolently stretching his arms above his head, elongating his spine on the third consecutive day it had swept Steve and him together. For the first time in the entire process, he liked being pregnant.</i>
</p><p>
  <i>Today, Tony stares into the mirror, runs his hand over the swollen skin of his belly, and tastes his old aversion souring the back of his tongue. </i>
</p><p>
  <i>He’s exhausting Steve now, and that’s a pretty massive claim to fame.</i>
</p>
            </blockquote>





	Join

**Author's Note:**

  * For [snottygrrl](https://archiveofourown.org/users/snottygrrl/gifts).



> Clearly In Tandem needed a sequel. Actually, it needs two, but the other one is only in the conceptual stages. Blah blah blah, stuff and reasons, here, have a fic.
> 
> For snottygrrl, because she loved the first one so much.
> 
> (Weighty A/B/O dynamics, but no non- or dub-con. Both parties are absolutely on board with all sex that occurs.)

The thing is, Tony’s not certain he’s actually awake.

He struggles with the blankets, befuddled when he can’t get his arm free. The air smells sweet and spicy, like cloves, and next to him, heat, more damp heat, tugging at his core just like he tugs at the blankets.

He groans, licks his lips. Something pulses down low, hitching his legs up, curling his shoulders. He finally gets his arm free and flails out, striking bare skin with a thump.

“Huh,” Steve mumbles in a burst, body twitching. His fingers clamp around Tony’s, thumb going straight to the hollow of his wrist and pressing where the vein throbs. Steve wipes his other hand over his face, a noisy snuffle.

Tony’s already gripping his way over Steve’s chest. Ribs slide beneath his fingers, the swift tension of muscle as Steve tries to sit up. “No,” Tony manages, “ngh,” but it’s fine, he’s got hold of Steve now, just needs to—he just— 

“S’okay.” Steve slumps back. His hands find their way to Tony’s waist, lifting, keeping the balance Tony can’t seem to manage anymore. There’s too much of his body these days, too hot, and he itches constantly inside where there’s only one way to scratch. Sweat salts his tongue; he feels it gathering suddenly at his temples and down his sides, clammy over his shoulders. Steve heaves up once more and stills him with a quelling grip at the nape. “Again?”

Tony doesn’t have an answer. Steve doesn’t wait. He kisses Tony, a shivery stroke deep into his mouth. He takes time with Tony’s teeth and tongue as though feeling his way in, and that juddering piece of Tony in the cradle of his hips eases its trembling for one blessed second.

Tony moans.

“S’alright,” Steve slurs, still tasting of sleep, “s’okay, here.” He lifts with both hands, and Tony straddles Steve’s naked hips and settles. Steve bends his knees to support Tony’s back, another constant discomfort eased. For a long moment Tony slumps into it, liquid and mind-fogged. But he can’t stay there, he knows it.

He feels like he’s constantly in Cycle. It pummels without warning, brings him low in the lab, in the kitchen, in bed in the flat darkness of night, and “If I could just rip this shit out of me, I’d—”

“I know.” Steve hitches further up on the bed for more leverage, and runs his hands over Tony’s swollen belly to the notch at his hips. Situates Tony even as he shushes him. He enters Tony’s body in one controlled thrust, a little twist of his hips at the end to seat him deep, and sends Tony’s next breath shaking out of him.

“That’s good, that’s—” Tony rolls his hips once, twice, three times in a winded stupor, hanging there on that glorious edge. Fucking _finally,_ it’s shutting the hell up. He swallows the stuttered moan forced from Steve’s lips. Steve thrusts up—he’s never able to help himself when Tony’s like this, and it’s delicious, it’s perfect. It brings Tony off in a convulsive quake that leaves his ears ringing.

When he can think again, he rocks back into it, half his mind on it, Steve’s fingers trembling over his burgeoning belly. Quick as flame, arousal sparks to life again, and Tony keens, half despairing, half thankful because with Steve in him and growing harder by the moment, thrusting up inside, _knotting_ right where everything is most tender—

God, he loves it when Steve knots inside him. It’s like this vast deluge, the crackling nerves silencing all at once, and he feels bigger, potent. Essential to Steve’s every thought. The last few months, Steve has knotted every single time they’ve done this. He can’t not do it; Tony senses the loss of control, the way Steve’s body just quivers, the way he goes from deeply asleep to alert in seconds, and he just seems to fit to Tony like they were originally one person. If this is what pregnancy does to a Joined pair, then Tony’s been a damned idiot.

It occurs to him in a muddle what he said earlier.

“Didn’t mean the baby,” he slurs against Steve’s lips. God, no. No, he’d never… Would he? Oh, hell, he doesn’t know what he’d do, he doesn’t even care as long as Steve stays locked inside him, fucking into him, pressing over and over where the itch is at its worst. Forever is fine. Whatever Steve wants, he’ll do. Cool swells of relief throb through his limbs, and he knows it’s the hormones, it’s all that procreative urge, protective and ridiculous and he doesn’t even know what they’re going to do with this baby when it finally gets the hell out of him, but right now, he’s okay with being one hundred percent on board. He’s okay with having offspring. He’s okay with his lover close enough to climb inside, smelling of heat and sweat and them.

They have a smell.

It’s not the same as the way Steve smells, and it’s not his own scent either. Tony thinks (when he’s not absolutely petrified by the entire thing) that it’s not the smell of him and Steve at all, but of the three of them: him, Steve, and this little… _being_ inside him. It’s the most curious, arousing scent he’s ever smelled and it surrounds him all the damn time.

He barely recognizes himself these days. His body is changing in the strangest ways, prepping for the birth, and Steve looks at him like he’s seeing him for the first time, like that moment when the Join first hit the two of them and Steve just froze in Bruce’s lab, halfway through a sentence, his fist tight against the tabletop as he fought the surge of responses, and stared at Tony like he was either going to hunt him down or tumble into a heap at his feet and stay there forever. Steve’s nostrils had flared, once. And Tony, vibrating with the wash of it himself, would already have been able to remember that stare for as long as he lives, but now he gets to repeat it _every damn day._

Steve thrusts up again with a grunt. His hands rise to Tony’s face. “You okay?” he breathes. His sweat smells like a clean, pure flood. Now that Steve’s locked into place, his movements go languorous, an endless undulation that will keep Tony thrumming for ages. It’s like scratching and scratching the most infernal itch in the universe while the euphoria just… keeps… coming.

Thank god Steve’s a super soldier; Tony has no idea how normal Joined pairs keep up. He has no idea how he himself hasn’t wasted away these last two months.

“Oh, god, I’m fine,” he moans, “I’m fine, I’m just, you’re perfect, you’re, don’t stop, don’t ever, whatever else you do, don’t.” He loses his train of thought.

Loses time.

**

He wakes with a head full of fog and that misery clawing its way back through his marrow.

All it takes is a touch, a sound he can’t help, and Steve’s pulling them back together, hushing Tony with almost-words, a steady stream against Tony’s lips, into his mouth, against his skin. Underneath, placid emotions nudge through the torment of his mind, diluting as they go: Steve’s never been so skilled at calming Tony through the Join as he is these days. He licks the sweat from Tony’s throat, kisses him stupid. Lays him back. Props Tony’s hips atop his thighs, and runs his hands continuously over Tony’s belly, and fucks the itch back into submission.

Tony _loves_ him for it.

**

Steve’s arm is a dead weight across Tony’s chest. He slumps full bodied into the mattress, the blankets rucked around him as though they’ve sucked him in. Nothing moves; his breathing is so sedate, it’s barely there.

When Tony gets out of bed, Steve doesn’t twitch at all.

**

Three hours later, the Avengers get a call-out. Tony begins the fight guiding the suit through the interface, and ends it bent at the waist, winded and bracing against his work table. Steve finds him in his lab in a right state.

“Tony.” He quickens across the room, letting the door swoop shut behind him. “JARVIS, no one comes in,” he growls. By the time he gets to Tony, he’s jogging, and Tony’s nose has filled with the scent of Steve, Join, Alpha, yes, _yesyesyes—_

Steve pulls the armored tunic over his head with one hand and grabs for Tony with the other. It’s a struggle to wrestle free of his pants, his body’s just so _weird_ now, but he does it and gets Steve against him, where he should have been an hour ago.

Steve’s fingers knead up Tony’s sides. “You should have told me.”

“You were fighting.” He doesn’t know words. These are lucky they made it out at all. He couldn’t distract Steve, Steve leads the team and that was no cakewalk out there, Clint took a robot to the face and Hulk—

“They’re fine,” Steve answers him, breathless. He shoves the shirt back over Tony’s shoulders. “Next time—”

“But I want you all the time, god, can’t you just—” The words clog in his gullet. It’s like a sickness, he has to purge this somehow, but all he can do is squirm against Steve and pull them together, and curse this pregnancy for doing this to his Joined. He loves sex with Steve. He lives for it, he’ll take any excuse. _Steve_ will take any excuse, but this isn’t natural, this is a lot bigger than Tony knows what to do with. He’s lucky if he gets six hours without that prickle plucking at the base of his backbone. It twines around his spinal cord, a twisted barber pole in red and darker red. He can stave it off for a while. It’s torture. He tests it every time, pushes and pushes until he’s delirious over the lack of Steve’s scent, and then Steve’s there. Steve always finds him, wrecked and outside of himself, but Tony always feels his pulse across the Join, perfectly in sync with his own. And for a moment, everything rights itself.

Steve hoists him onto his worktable and Tony braces, falling back to get his stomach out of the way. And then Steve’s in him again just where he needs to be, driving hard, hands crawling over Tony, mouth open and muscles bunching. Tony’s thirst spirals even higher; he can’t function when Steve looks like this, all bare and faultless, eyes so dark, locked on Tony like he’s thinking of devouring him. His uniform trousers are halfway down his thighs, hips pistoning, hitting—right—there—

“Steve,” Tony chokes as his climax rushes over him, surge upon surge. He’s sore, but he doesn’t hurt, he just tumbles in it, bowled over and over. He can’t remember ever having orgasms like this, climaxes that refuse to let go, like he’s stuck in an undertow. 

When it finally trickles away, he’s flat on his back on the table and Steve is collapsed over him, heaving against his shoulder.

“Fuck,” Tony wheezes, winding his fingers through Steve’s damp hair, “fuck, fuck, fuck,” because even under the rush of endorphins, he can feel the itch curling tighter again.

Steve kisses his face sloppily. His words run together. “You alright, you’re…”

“Yes,” Tony hisses. He takes Steve’s face in both hands, rights the kiss. Forces everything back down; for now, the smell of them will be potent enough to hide it from Steve’s overly receptive senses. “I’m good. Sleep.”

Steve groans, eyes drooping shut as though the lids have weights attached. He lolls to the side, breaths evening even as Tony watches. His muscles go disturbingly lax.

** 

“Fuck you.”

The heat shivers invitingly. Tony clamps his lip between his teeth and tightens screw after screw. The room is getting hotter, but he’s not done, damn it. 

Mind over matter. That’s his middle name. 

“I will get to you—” He grunts, bending down for a better angle, and cranking the wrench. “When I’m good—” Crank. “And ready.” Crank.

A tremor rolls up his spine like a hand sweeping, and Tony shudders. Fuck, his libido has turned into a rhino on PCP. “Joke’s on you,” he tells it. “I’m already pregnant, what more do you want?”

He braces on the table and takes a deep breath. He’s going to finish this, and Mother Nature will just have to wait for Steve to figure it out and show up.

**

At the start of his sixth month carrying, Tony tried keeping it under the radar. As it turns out, it’s hard to do that when Steve can smell even the tiniest flicker of his distress.

Now Steve always finds him, always seems to be thrumming, more aware of Tony than anything else. Tony gave up hiding it when the discomfort became debilitating, when Steve’s stress began to skyrocket, and finally, when he went to the doctor and was instructed that under no circumstances was he to attempt to smother this urge.

Fucking blood work, out of whack again. Tony loathes his body.

Oh, he knows what _this_ is. This is the Omega trying its damnedest to strengthen the Join to its Alpha before the birth of offspring. It’s old school, and offensive; Tony can take care of himself, thank you. He hasn’t needed any other person, let alone Steve Rogers, to save his ass for decades. Adding a child to the mix will complicate things, but Tony is fairly certain he’s clever enough to keep this kid safe. His body chemistry, however, hasn’t gotten with the new age protocol yet. It demands this stronger bond with sharp teeth and raking claws, and Tony can barely control his own thoughts when it latches into him, never mind his libido.

He hasn’t been this well-sexed in ages. And he hasn’t felt this horribly bereft in just as long.

In the beginning, it was exquisite. Ingenious of nature to come up with this, he’d thought, soaked in sweat and indolently stretching his arms above his head, elongating his spine on the third consecutive day it had swept Steve and him together. For the first time in the entire process, he liked being pregnant. Adored it. Didn’t care about any of the worries or the dread. Something inside him was tender all the time, extra sensitive, and whenever Steve got inside him too, everything became three times as raw, every single thrust hitting just where he needed it, every orgasm swiping his mind white and lasting longer than the one before.

So Tony came for ages, then stretched out in their bed with a guttural groan. Steve rolled off of him with a weak laugh and glommed on instantly, hands fixed around Tony’s waist, leg pushing back between Tony’s, sweat slicking his and Tony’s skin alike. “Well, shit,” Steve mumbled.

“Right?” Tony was beyond elated, feeling the odd kick and shuffle of the creature living under his ribs. He fancied he was getting used to that part, too, and it wasn’t as invasive as he’d feared. “We can, you know.” He remembers gesturing, feeling like he could grasp the whole world in his palm at once. What a huge difference in how he felt about this just ninety days ago. “Can do that. For four more months, I’m okay with that, I’m…”

Steve leaned over and kissed him, a thorough tonguing that stirred the coals all over again, and the second time, breathless and on heavily battered nerves, was even better.

It has now been two months since that day, and a month since he tried concealing it. Tony’s nerves are battered all the time, and not in the best ways.

Today, Tony stares into the mirror, runs his hand over the swollen and striped skin of his belly, and tastes his old aversion souring the back of his tongue. 

He’s exhausting _Steve_ now, and that’s a pretty massive claim to fame. 

**

“That’s all I’m saying, Tasha, that it’s a problem.”

Natasha sighs. “I’m not arguing with you, am I?”

“We need to do something.”

Tony watches the feed from his lab, watches Clint fist his hands against the kitchen tabletop, then flatten them, palms down. Across the table from them both, Bruce takes off his glasses and rubs his eyes. He opens his mouth but Natasha beats him to it with a sudden burst of laughter.

“Like what?” Her lip curls. “You want to be the one that tells Tony he can’t sleep with Steve anymore?”

“Oh, hell, no,” Tony mutters, scowling.

 _“Hell,_ no,” Clint answers, raising his hands like he’s being robbed.

“Look,” Bruce begins.

“You brought it up,” Natasha says silkily.

“Guys,” Bruce says, but Clint points a finger at Natasha’s forehead.

“Only because _you_ were muttering about how screwy it is when you two can’t even scrape a battle plan together anymore. You think I want to go into a fight wondering if my fearless leader’s going to take a header off a building because he can’t remember why the hell we’re there?”

Tony frowns harder. “Hey,” he whispers.

“Hey,” Bruce interjects, “Steve has never let us down on the battlefield.”

“Which is why one of us needs to say something, now,” Natasha answers, leaning forward on her elbows.

“Thank you!” Clint throws up his hands and sags into his chair. “Shit.”

Bruce exhales loudly. “Thor?”

“I will admit,” says Thor slowly, his attention fixed on the fork he’s been toying with for the past minute, “that I have noticed a certain… lethargy in our captain’s demeanor of late.”

“Well, yeah,” Bruce says, holding out his hands. “He’s got a lot on his plate, don’t you think?”

In his lab, Tony mirrors him. _“Thank_ you. Jeez.”

Clint huffs. “If by ‘a lot on his plate,’ you mean a damned sleeping sickness.”

“Wouldn’t you be tired?”

“It is not safe,” Thor says lowly. It quiets everyone, and three floors down, Tony goes still. Thor takes another moment, then sets the fork down with a decisive clink. “This cannot go on as it has.”

They all seem to know, even Tony, that Thor’s not talking about the sex.

**

He wakes to Steve stumbling out of bed, the thump of his feet against the carpet. Tony’s battling out from under a mantle the likes of which he’s never felt before pregnancy. At night his body retreats into a dormant state, roused only for nourishment or the sating of this eternal itch. It takes him a minute to figure out where he is, and by then, Steve is at the door to their room.

“JARVIS,” Tony hears him mutter. “Security sweep.”

“Running, sir.”

“Steve?” Tony pushes up, foiled by his own weight. It’s just wrong that Steve should leave, that he should not be here right next to Tony. Steve fumbles for the doorjamb, swaying when he misses. It pricks Tony that much further awake. “Steve.”

“Where are they,” Steve mutters. He inhales once, then again, a third time, and Tony understands with a sudden shock that Steve is sniffing.

“Where are who? JARVIS—” He shoves the bedclothes free and finally rises, scrubbing at his face. The intensity hums as always, but banked back for now, thank god. Steve sniffs again, long and deep, and Tony freezes. “JARVIS, is there anyone in the tower who shouldn’t be here?”

“Negative, sir. Scans show that all floors are secure and have been for the last four hours.”

Steve sways again. Tony gets close enough to see him blink rapidly. He stumbles toward the hall, but Tony grabs him, pulls him back. “Steve, what is it?”

“Someone here.” Steve sounds washed in sleep, guttural in a way that skitters up and down Tony’s neck. “Alpha.”

“JARVIS.”

Immediately, projections flicker all over the room, bathing them in blue. Feed after feed lines up, empty hallways, quiet corridors, closed doors. Bruce is up in the team lounge, sprawled on the couch watching television, but he’s the only one still awake. Tony summons the emergency feeds, and Steve’s gaze flickers to them one after another, taking in Natasha fast asleep in bed, Clint crashed out on the couch in his quarters, Thor snoring visibly. Sam’s bed is vacant, neatly made, but he’s been out of the tower for the last week, and Rhodey’s been on assignment for months. All the other guestrooms are empty. Downstairs, the doors are locked fast, laser sweeps visible by infrared and running in grids. The roof is completely barren.

Tony leans out into the darkened hallway and sniffs the air himself, but there’s nothing. Nothing but Nat and Clint and Bruce and Thor. And Steve, the aroma of him heady with danger.

“I could smell them.” Steve frowns at the wall. His eyes have dark circles under them, his mouth pinched at the corners. “But now…” His jaw works in silence for a moment. “Now there’s nothing.”

Tony understands at last. “JARVIS, play back Steve’s recent brain activity.”

An intense dream, by the look of it, activating all the sensory receptors that normally lie dormant. Steve’s brain chemistry is not at unhealthy levels, but it is insanely active, adrenaline firing, endorphins switching on like clockwork.

Steve slumps. One by one, the feeds flicker off until all that’s left is the medical playback. “Oh god,” he whispers, and puts a hand over his face. “Oh god.”

“It’s okay.” Tony rubs his arms, his throat, his chest, pushing his scent over Steve and watching the brainwaves begin to settle, in real time. “No one here but me.”

“They were here.” Steve’s hands have found their way to Tony, absently slipping up and down his sides. “They were… I could have sworn.”

“I know.” With the adrenaline fading, the itch is welling back up. Tony cannot do this to Steve now, but he may not have a choice. He takes a deep breath and wills it down. Steve’s hands trek round to his belly, his back, never lifting completely away. “You know Natasha would have been on them the second they breached the lobby.” Natasha’s sense of smell is incredible, the most refined of all of them on a normal day. Lately, Tony has wondered if it hasn’t been refining itself further, honing in little chisels as his own scent amps and morphs.

Steve stiffens; Natasha is still Alpha. Not a danger, but the instinct is difficult to erase. Tony knows this from experience. Even he jumps a little these days when Natasha sweeps into a room. The fact that she doesn’t do it often anymore is part of his slowly gathered evidence that she can smell him coming from much farther away than she ever used to.

She avoids Tony when she can for Steve’s sake, and Steve makes a monstrous effort to associate with her on terms they can both handle. Brief walks, outings for food or drink. Not in big crowds if they can help it. Never sparring; much too volatile. None of them are going to let this insanity bust up the team, but it has required some adjustment. 

Tony wonders, not for the first time, if Steve’s current mix of scents scares her.

“But you’re okay.” Steve’s not really asking. He stares for a moment at Tony’s stomach, then tracks him head to toe the way he sweeps a battlefield, eyes flicking over every detail, filing all into place. “You’re okay.”

“I’m fine.”

But Steve’s nostrils flare. His focus tightens before Tony can prevaricate, and he looks Tony directly in the eye. “Are you?”

 _“Yes.”_ He stills Steve with the force of the word. Takes a breath too, but he’s never been able to smell his own arousal like Steve can. “You are exhausted, we’re not doing this now.”

“If you need it—”

“I need you to be here. That’s all. I need you to be safe, and as well rested as you can be, and god knows I’m not making that easy.”

Steve noses into his hair, and Tony shudders into silence. He waits while Steve shifts, pushes his nose along the side of his face. Down toward the hollow beneath his ear. Steve pauses. “You _are_ okay.”

Is it fading? God, he hopes so. The surprise in Steve’s voice is apparent, but the relief even more so. Inside Tony, the baby turns over, and he fights off a very different sort of shudder. 

Oh, hell, he’s half asleep, they both are. He can’t be held responsible for his reactions. “Come, come on, bed. JARVIS.” He forgets what he was going to say.

“Activating security measures for individual suites.”

Only then does he feel Steve start to relax. That’ll do. He urges Steve down onto the mattress again and follows him awkwardly. He just wants to fall asleep before this shit catches up to them again.

**

The alarm goes off, and Steve jumps, a full-body spasm in Tony’s arms. Tony clamps onto him, instinctive, and can’t make sense of the noise, the heat, the anything. “Shut it off,” he slurs, “JARVIS, shut it.”

“I cannot, sir,” as the alarm blares on and on. “It is a Level Three alert.”

Steve lies there completely motionless, and Tony risks a glance at his face. His eyes are half-lidded, but his breathing is accelerating, his body waking itself up out of necessity. After a second, he groans. A hand climbs over his eyes. “JARVIS,” he says, straining to be heard over the noise. “Input Rogers two-three-oh-three-five delta.”

The alarm slices off inside their room, but continues to ring beyond the door. Screens flicker on: Clint already powering up the jet, a city-wide map zeroing in on the source of the disturbance, a communiqué between Sam Wilson and Natasha. Steve struggles halfway up and groans again. He barely gets an elbow behind him to brace before falling back.

Tony sits up. “Steve.”

“I’m fine.” But he’s not. He blinks rapidly. Passes a hand in front of his eyes as though he’s having trouble seeing it. He smells off, a heavier version of the way he’s smelled for months: too sharp, too wild. It’s sublime in Tony’s nose, but the logical half of him knows it’s not the way it should be. Steve’s shoulders hitch once.

And then he drifts—that’s the only word for it—back down to the mattress, like he’s unfolding.

A surge of lust shoots through Tony’s core, but the incisive understanding is the more powerful. “JARVIS, get me Natasha. Now.”

 _“Stark?”_ she says a moment later.

“What’s the threat assessment?” he asks, eyes on Steve’s supine form.

_“Four combatants. Mutants by the looks of things. Suburban area, six minutes to intercept.”_

And he’s never wanted to say this, but in a way, he always has— “Can you do without Steve?”

_“Are you alright?”_

“I am.”

A pause. _“Understood. We’ll take care of it.”_

The comm clicks off. Steve twitches, a hand bumping against Tony as if to grab him, but Tony locks their fingers together instead. It must have been in his voice; he has no idea what he sounded like over the comm, but he can almost hear it now, an audio after-image.

He sounded raw.

“What do you need?” he asks, leaning over Steve, bracketing his head with his arms. Steve’s hand climbs up his side.

“Whatever you need,” he murmurs. His eyes are still half-lidded. The scent of arousal on him surges, overlaid with the faint sourness of fatigue. Tony’s body answers in kind; it always answers Steve. Steve always answers him.

But what Tony needs right now is not sex. An argument spikes and he forces it down with an unexpected burst of anger. Looking at Steve, at the hollows under his eyes and the pull at his mouth, is more than enough.

“Need you,” he whispers. He can’t help lipping at Steve’s mouth anyway, because, Steve. Oh, Steve. Tony could fold into him. He brushes his nose along Steve’s bottom lip and feels the rush of air exhaled. “Near me,” he finishes.

Steve’s too tired to sort through what Tony’s not saying. Too tired to smell it on him, and that latches into Tony’s gut like a hook. Fuck this shit, he thinks, they’re sleeping. He doesn’t care if the baby births itself out of spite. He’s putting Steve to bed.

“Come here.” He pulls Steve’s arms and legs around him, moves as close as he can. Steve strokes Tony’s body as though he can’t help himself, arms moving lazily, fingers trailing. His eyelids flutter; Tony gets a glimpse of white and bites his tongue. “Steve?”

Just a grunt, not even a word. Steve breathes like he’s been running. Tony latches around his wrist with a shaking hand, counting the beats of his pulse. Too fast, surely that’s too fast. “JARVIS,” he whispers, “analyze Steve’s vitals, would you?”

“Heart rate is elevated,” JARVIS responds just as softly, “respiration shallow. Body temperature is one-oh-one-point-six.” About a degree over Steve’s normal. “None of my readings indicate immediate danger, but they are on the upper end of his average spectrum.”

Tony’s willing to bet he’s low on salt, too. Steve’s not sweating, even with the increased temperature. “Keep an eye on him. Anything jumps, call medical.”

“Understood.”

What can he do? There has to be something that doesn’t involve him straining Steve further. Tony kneads his eyes, frustrated. All he’s got is sex, and it’s completely superfluous, seeing as how he’s already well knocked up. It’s still curling in him, eddying like it can’t decide if it wants to erupt. If he thought Steve wouldn’t drag himself through the Tower after him, he’d retreat to the workshop, which is as far away from the penthouse as he can get and still stay on the residential levels. He could lock all the doors between them, throw up ten Stark-made security measures, and he knows he’d just be doing more harm to them both.

“Alright,” he sighs. It feels good to hold Steve. If the sex relieved Steve’s discomfort even a tenth of the amount it relieves him, he’d fuck Steve until he has to actually stop and have this baby—

Tony stills.

There is a moment, during each Week—and _obviously_ it hasn’t occurred to him, fuck’s sake, they haven’t had a Week since he got pregnant—when the thrum slows, the current quiets, and all Tony wants is Steve in him. Never a conscious choice: it’s always the culmination of the final grueling bout, when Steve sags down atop him, arms shaking as he tries in vain to hold himself up, or Tony drops full against his lover, trying to meld their bodies in all the ways they aren’t already united. Then Steve’s knot isn’t even a reality: just him, fitted into place inside Tony like he’s meant to be. Tony doesn’t need to move, or eat, or drink. Doesn’t feel like he needs to sleep, though they do, always. Whole days pass like that; it’s enough to simply… be.

Just maybe, Tony thinks, looking at the exhaustion in Steve’s face, it’s the same now.

His heart bumps staccato as he turns carefully in Steve’s arms, trying not to disturb him. But Steve murmurs anyway; his hands clutch at Tony, so gentle even as he tries to still his motion. “Wait,” Steve slurs, pushing his nose into Tony’s hair, and Tony kisses him, slow, holding his face in both hands. Steve’s muscles lose a smidgen of their tension.

“I just want to try something,” Tony says against his mouth. He turns in Steve’s arms until his back is to his lover, keeping as close as he can. He has spent a straight four months ready for sex at every hour of every day; getting Steve in him won’t present a problem. Steve stirs as Tony guides them together, restless for a moment, and Tony hears him wake up a little more, formulate words. 

He doesn’t wait to hear them. It feels sinful to get Steve in him, warm water over inflamed flesh. Tony fights the immediate urge to thrust back into it, find them a rhythm and ride it to its end.

He battles it for almost a minute, and grabs Steve’s hip to still him, too. Grits his teeth against it even as Steve shifts forward, and—

It drops away, smothered by a sluicing euphoria. 

“Oh,” he moans, but it’s Steve’s sudden heave that opens his eyes: his mate trembles once, full-bodied, and then every muscle in his frame goes slack, his arm hanging heavily against Tony’s ribs. Steve’s hand comes to rest splayed over his belly. One knee creeps sluggishly between Tony’s, spooning them together, and Steve nudges into Tony’s nape, nose resting just under his ear. Tony can feel each breath in and out, a beautiful flutter.

He reaches up, already feeling like he’s moving through molasses, and cradles the back of Steve’s head. The smell of them is too blanketing, but he imagines a change in Steve’s scent. Something quieter, normal.

 _Much too soon for that,_ logic mumbles. But it’s hard to think. Everything in him seems to be winding down, pulling inward and redirecting. The baby moves, a languid roll, and it feels right to have Steve curl that last inch closer, until everything clicks.

The urgency he has forgotten to notice is just _gone._

Tony drags Steve’s hand to his mouth and kisses his palm. Tongues the warm flesh at the heel of his thumb, then folds their hands together against his heart. Steve whispers something into the side of his throat, and Tony feels the hum beneath his skin.

~fin~


End file.
